U4 



in two days. Powdered brimstone mixed with New- 

 castle coal,* neither generated nor absorbed. 



An inch of chalk, and as much oil of vitriol, in three 

 days generated 31 inches of air. Part of this it after- 

 wards resorbed. Two inches of lime, and as much sal 

 ammoniac, absorbed 115 inches. Tiie fumes of this 

 are therefore very suffocating. All burning and flaming 

 bodies absorb much air. And whereas the air which 

 some substances absorb is afterwards remitted, that 

 which is absorbed by burning brimstone by the flame of 

 a candle, or by human respiration, does not recover its 

 elasticity. 



The elasticity of the air in the vesicles of the lungs is 

 continually decreasing through the vapour it is there 

 loaded with, so that there needs fresh air continually, 

 otherwise those vesicles will soon fall flat, whereby the 

 motion of the blood through the lungs being stopr, in- 

 stant death ensues. And this seems to be exactly the 

 case of most of those who are killed by lightning, which 

 so totally destroys the elastic air in the lungs, that they 

 instantly fail flat. 



31. Many have imagined that the animal fluids are 

 furnished with air by the lungs only. But undoubtedly 

 they are also supplied therewith by way of the chyli- 

 ferous canals, and that in no small quantity : for*the 

 air, like all other animal fluids, requires to be perpetually 

 renewed; accordingly old particles fly oflf every moment, 

 and new ones succeed in their place. 



It may fee demonstrated, that urine contains much 

 air. Doubtless so does the perspirable matter, which 

 being the lightest of all animal- fluids, is the chief 

 vehicle of the effete and useless air. 



And that candles soon go out, if they are confined in 

 a small quantity of air, seems not to be so much owing 

 to their having rendered the air effete, by consuming its 

 vivifying spirit, as to its destroying the elasticity thereof 

 by its acid, fuliginous vapours. 



But nothing destroys the elasticity of air like brim- 

 stone, whether burning or in fermenting mixtures. And 



